The present disclosure discloses a phase-shift unit, an antenna array, a display panel and a display device. In one embodiment, the phase-shift unit includes a first substrate and a second substrate assembled to each other; a liquid crystal layer between the first substrate and the second substrate; a microstrip line provided at a side of the second substrate facing towards the liquid crystal layer, and configured for receiving a voltage signal that controls deflection of liquid crystal molecules in the liquid crystal layer and for receiving or transmitting an electromagnetic wave signal; and a grounding layer provided on the first substrate and including a via hole corresponding to the microstrip line.